The invention concerns a driving mechanism for motor vehicle roofs having a cover that can be slid and/or tilted out with respect to an opening in the roof, with the cover being movable by means of an electric motor, through at least one incompressible driving cable, with said electric motor being mounted in front of a front side of the opening of the roof on a stationary part of the roof, and by means of a secondary drive wheel of an intermediate drive that drives a pinion which engages in the driving cable and is arranged essentially on a central longitudinal axis of the motor vehicle, with said intermediate drive being disposed in a gear housing to which the electric motor is flanged forming a drive unit.
A driving mechanism of this type is known (DE-GM 78 01 538 and corresponding to U.S. Pat. No. 4,272,125). In this case, the electric motor is installed in front of the front side of the opening in the roof, so that it is located at a point where a crank drive of a manually operated driving mechanism must be located in order to be reached conveniently by the driver, as well as the front-seat passenger. In this manner, a relatively large number of identical parts may be used for motor drives and manual drives to be provided selectively. Additionally, this known mechanism has the driving pinion, its pinion shaft and the secondary drive wheel firmly connected with one another. Despite the installation of the electric motor at a point where, in the case of manually operated roofs, the crank handle is located, the selective use of motor drives and manual drives presents problems.
Thus, the present invention has for a primary object, the creating of a drive mechanism where the number of its parts, which are common to those used with a manual drive mechanism, are maximized.
According to a preferred embodiment of the present invention, this objective is achieved by means of the fact that the secondary drive wheel of the intermediate drive is detachably connected with the pinion shaft through a sliding pinion and stem gear, and that the drive unit comprising the electric motor and the intermediate drive may be exchanged for a hand crank, which is provided with the gear elements corresponding to the gear elements of the secondary drive wheel. The driving pinion, the pinion shaft and the pertaining bearing also become standardized parts, i.e., parts which a roof with a motor drive and a roof with a manual drive have in common.
This is especially significant when the driving pinion, as known from DE-OS No. 29 14 855 and its counterpart U.S. Pat. No. 4,332,416, is part of a preassembled installation unit which comprises at least the driving cable, cable-guide ducts, guiding tracks for guide shoes carrying the cover, as well as the guide shoes inserted into the guiding tracks. The reason for this significance is that the preassembled and preadjusted installation unit of the roof can then be produced in an identical manner, irrespective of whether it is to be utilized with a manual drive or a motor drive, so that a drive unit comprising an electric motor and an intermediate drive or a hand crank can be mounted without additional parts.
The drive unit is preferably generally V-shaped in plan view, and one leg of the drive unit is disposed transversely to the center longitudinal axis of the motor vehicle and contains the electric motor, while the other leg receives the intermediate drive and carries the pinion. This configuration is similar to the mechanism known from DE-GM 78 01 538 and U.S. Pat. No. 4,272,125, and makes the electric drive, extending transversely to the longitudinal axis of the motor vehicle, short enough to fit between depressions, which are generally provided for receiving sun visors, in a headlining layer covering the interior of the roof of the motor vehicle; despite the fact that the point of the motor shaft that engages with the intermediate gear is inevitably disposed laterally outside the central longitudinal axis of the motor vehicle, the driving pinion can be disposed on the central longitudinal axis of the motor vehicle.
The gear elements of a drive coupling may suitably be formed by notched teeth that can be engaged with one another. An especially strong construction is achieved if the drive coupling is formed by an outside serration of a gear element located at one end of the pinion shaft and an internal serration of the secondary drive wheel of the intermediate gear or of a secondary drive shaft carrying said secondary drive wheel, and the hand crank has an internal serration corresponding to the internal serration of the secondary drive wheel or the secondary drive shaft. For the pinion shaft gear element, a diameter is sufficient that is not, or not much larger than, the diameter of the pinion shaft. For that reason, in order to simplify the construction, the gear element and the pinion shaft can advantageously be unitarily formed with one another as a single piece.
In order to be able to still operate a roof having a motor drive when the motor drive is out of commission, the secondary drive wheel or the secondary drive shaft carrying said secondary drive wheel is, preferably, at a side facing away from the driving pinion, provided with an inside polyhedron, such as an inside hexagon, for matingly connecting with an emergency tool, such as an Allen-type wrench.
These and further objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a single embodiment in accordance with the present invention.